JP4172023B2 - Shield excavator, tunnel widening method and tunnel narrowing method - Google Patents

Description

The present invention relates to a tunnel widening method and a tunnel narrowing method .

  Conventionally, since it is necessary to install a station part and an emergency parking zone in a subway tunnel or a road tunnel, it is often necessary to provide an enlarged pit having an enlarged cross section in which a wide cross section is combined with a standard cross section. When constructing such a tunnel by the shield method, the size and shape of the shield tunnel depend on the size and shape of the shield excavator itself because the segment is constructed inside the shield excavator. Therefore, in the shield tunnel, the cross section becomes an enlarged cross section over the entire line, which is uneconomical.

Under such circumstances, as shown in Patent Document 1, a shield excavator is manufactured in an enlarged cross section that combines a standard cross section and a widened cross section, and an enlarged cross section tunnel is formed using the entire cross section of the shield excavator. A method of building a tunnel with a standard cross section in the remaining space has been developed in which a water blocking block having the same shape as the wide cross section is installed in the shield excavator at the standard cross section.
Japanese Patent No. 2799905 (see FIG. 1)

  However, in the shield tunnel construction method described above, when the cross section is switched from the standard cross section to the enlarged cross section, the water blocking block is discharged to the outside of the shield excavator, and the extra moat between the ground and the standard cross section is generated. Leave it on the head. For this reason, in a shield tunnel that repeats widening and contraction over the entire length, it is necessary to manufacture a plurality of water blocking blocks, which is not economical.

In view of the above circumstances, an object of the present invention is to provide a tunnel widening method and a tunnel narrowing method capable of economically expanding and contracting a tunnel with a simple configuration.

The tunnel widening method according to claim 1 is a tunnel using a shield excavator for constructing both a general mine having a standard cross section and an enlarged pit comprising an expanded cross section in which the general mine is combined with a widening pit having a wide cross section. The shield excavator includes a skin plate having a cross section similar to the enlarged cross section, a cutter positioned in front of the skin plate and excavating a general pit and a wide pit, and the skin plate The shield includes a temporary tail member that is detachably disposed at the rear and between the inner peripheral surface and the outer peripheral surface of the standard cross-section segment assembled in a ring shape, and has the same cross-sectional shape as the widened cross-section. while excavation in enlarged cross-section the combined standard views and widening sectional using excavators, assembling the standard cross-sectional segment by the skin plate in a temporary tail member is mounted, digging A first step of constructing a general well in a later standard cross-sectional area, and a standard cross-section segment including a blocking mechanism for blocking an extra portion of the widened cross-sectional area before and after the tunnel axis in the general well, A second step of cutting the extra-drilled portion before and after in the tunnel axis direction using the blocking mechanism after assembling while assembling the cross-sectional segments; and removing the temporary tail member from the skin plate; After fixing the widening block having the same cross section to the outer peripheral surface of the standard cross section segment assembled in the second step, the expanded cross section segment is expanded to the expanded cross section area after assembling and excavating with the shield excavator. It consists of the 3rd process of constructing.

The method for reducing the width of a tunnel according to claim 2 uses a shield excavator that builds both a general mine having a standard cross section and an enlarged mine composed of an enlarged cross section including a wide pit having a wide cross section in the general mine. A method for reducing the width of a tunnel, wherein the shield excavator includes a skin plate having a cross section similar to the enlarged cross section, a cutter positioned in front of the skin plate and excavating a general pit and a widening pit, and the skin A temporary tail member is provided behind the plate and detachably disposed between the inner peripheral surface of the plate and the outer peripheral surface of the standard cross-section segment assembled in a ring shape, and has the same cross-sectional shape as the widened cross-section, wherein while excavation in enlarged cross-section the combined standard views and widening sectional using shield excavator, assemble the enlarged sectional segments provisionally tail member removed the said skin plate, drilling First a step, said enlarged pit, after assembly of the standard cross-section segment which is fixed to the outer peripheral surface of the widening block with the same cross-section and the wider cross section, the standard cross-sectional segments of building an enlarged hole in enlarged cross-section area after A second step of mounting a temporary tail member on the skin plate, a third step of assembling a standard cross-section segment while excavating the shield excavator, and constructing a general pit in the standard cross-sectional area after excavation It is characterized by comprising.

According to the tunnel widening method of claim 1 , a standard cross-sectional segment having a blocking mechanism is assembled in a general mine, and according to the tunnel narrowing method of claim 2 , After assembling the standard cross-section segment with the widening block fixed at the switching position, the widening cross-sectional area is cut off at the predetermined position at the front and rear in the tunnel axis direction. The widened cross-sectional area corresponding to the groove portion can be blocked. As a result, even when switching the tunnel from a general mine to an enlarged mine, or even when switching from an enlarged mine to a general mine, the surplus area adjacent to the general mine can be stopped easily, resulting in good workability and reduced construction costs and construction time. It is possible to contribute greatly.

  In addition, since the excavation cross section by the shield excavator corresponds to the expanded width section that combines the standard section and the expanded section over the entire length, even if the shield tunnel repeats expansion and contraction in the middle, the ground will not be affected. It becomes possible to construct without considering the constructed structure.

  Furthermore, even when constructing a shield tunnel for ground where the ground conditions change as it digs up, the shield tunnel can be mechanically constructed in a uniform procedure, so compared with the widening method by ground improvement. Therefore, it is possible to construct a safe and high quality shield tunnel with good workability.

1 to 7 show an embodiment of a tunnel widening method and a tunnel narrowing method according to the present invention and a shield excavator used therefor . The present invention relates to a shield excavator provided with a skin plate having a cross section corresponding to an enlarged cross section of a tunnel , and a temporary tail member formed in a cross section corresponding to an enlarged cross section installed detachably behind the skin plate. Is used to build a tunnel with both a standard cross section and an enlarged cross section in which a widening pit is combined with the standard cross section.

(First embodiment)
As shown in FIG. 1 (a) and FIG. 2 (b), the shield excavator 1 includes both a general mine 14a having a standard cross section and an enlarged mine 14c having an enlarged cross section including a widening pit 14b adjacent thereto. This is a device for constructing the shield tunnel 14 provided with the skin plate 2, the cutter 3 and the temporary tail member 7.
In the present embodiment, the cross-sectional shape of the general pit 14a is a circle, the substantially rectangular shape in which the cross-sectional shape of the widening pit 14b is curved, and the cross-sectional shape of the expansion pit 14c is a cross section of both the general pit 14a and the widening pit 14b. However, the cross-sectional shapes of the general well 14a and the widening shaft 14b are not necessarily limited to this.

  The skin plate 2 is a cylindrical body that forms the outline of the shield excavator 1, and has a cross section corresponding to the enlarged pit 14 c of the shield tunnel 14. Further, the cutter 3 provided in front of the skin plate 2 corresponds to a disc-shaped cutter 3a for excavating a region corresponding to the general mine 14a and a widening pit 14b, as shown in FIG. 1 (b). A square disk-shaped cutter 3b for excavating a region to be drilled is provided. The cutter 3 rotates a cutter bit 3c installed in the front to excavate a natural ground, and the shield excavator 1 always excavates the natural ground 15 in a cross section corresponding to the expanded mine 14c. In addition, the shape of these cutters 3 is the same as the cross-sectional shape of the general mine 14a and the widening pit 14b, and does not necessarily stick to this.

  2A, the shield excavator 1 has a chamber 4 for taking excavated soil into the back surface of the cutter 3 inside the skin plate 2 and the excavated sediment in the chamber 4. As shown in FIG. It includes a soil removal device 5 for soil removal, and is arranged on the inner wall of the skin plate 2 with a predetermined spacing in the circumferential direction, and extends in the direction of excavation to ring behind the thrust receiving piece 10 or the skin plate 2 A pressing jack 11 is provided to press the segment 9 assembled into a shape and to advance the shield excavator 1.

Further, as shown in the horizontal sectional view of FIG. 2B, a tail packing 6 that contacts the outer peripheral surface of the segment 9 is provided on the inner wall behind the skin plate 2. The tail packing 6 uses a configuration in which wire brushes are attached in a multiple manner, but any tail packing 6 may be used as long as it can prevent the backfilling injection material and the groundwater from flowing into the skin plate 2.
The shield excavator 1 having such a configuration excavates a region corresponding to the widening pit 14b of the shield tunnel 14 on the inner wall behind the skin plate 2, as shown in the horizontal sectional view of FIG. A temporary tail member 7 is provided at a position coaxial with the cutter 3b in the direction of excavation.

  The temporary tail member 7 is used when a general pit 14a having a standard cross section is constructed at a position where the segment 9 is assembled behind the skin plate 2. Therefore, it has the same cross-sectional shape as the widening pit 14b, but a notch is provided at a position where it abuts on the tail packing 6 provided in the skin plate 2, and the segment of the standard cross section is provided. A tail packing 6 having a function similar to that of the skin plate 2 is provided in contact with the outer peripheral surface of the segment 9a of the standard cross section at a position facing the 9a. The temporary tail member 7 is disposed so as to be inward from the rearmost end of the skin plate 2.

  Further, the temporary tail member 7 is detachably installed on the skin plate 2. When the general pit 14a of the shield tunnel 14 is to be constructed, the temporary tail member 7 is attached and when the expanded mine 14c is to be constructed. By removing, the segment 9 according to the cross-sectional shape can be easily assembled.

Further, the temporary tail member 7 is provided with a backfill injection mechanism 8 including an injection pipe 8a and a discharge port 8b. This is because when the expansion pit 14c of the shield tunnel 14 is constructed, the area corresponding to the widening pit 14b becomes a surplus portion when the general mine 14a is constructed. Further, the backfilling injection material 16 is injected into this surplus portion.
The backfilling injection mechanism 8 is supplied with the backfilling injection material 16 from the injection pipe 8a and discharges it to the surplus portion through the discharge port 8b. The injection pipe 8a is a backfilling injection material. Any device that can supply 16 may be connected. In the present embodiment, for the purpose of reusing the excavated sediment, the injection pipe 8a is configured to communicate with the chamber 4 via the soil removal device 5, and cement water and admixture are supplied to the excavated sediment and backfilled injecting material. 16 is supplied to the backfill injection mechanism 8.

A tunnel widening method and a narrowing method using the shield excavator 1 having the above-described configuration will be described below. The widening of the tunnel is to switch the shield tunnel 14 from the general pit 14a to the expanded pit 14c, and the reduced width of the tunnel is to switch the shield tunnel 14 from the expanded pit 14c to the general pit 14a.
First, the tunnel widening method will be described in detail with reference to FIGS. 3 and 4 show horizontal cross sections of the shield excavator 1 and the shield tunnel 14.

(Wide widening method: first step)
As shown in FIG. 3 (a), the skin having the temporary tail member 7 mounted thereon while excavating a natural ground 15 with an enlarged cross section 1c obtained by combining the standard cross section 1a and the widened cross section 1b using the shield excavator 1. The standard cross-section segment 9a is assembled in the plate 2, and the general well 14a of the shield tunnel 14 is constructed in the region having the standard cross-section 1a.

  At this time, since the region having the widened cross section 1b formed between the standard cross-section segment 9a and the natural ground 15 becomes an extra excavation portion, the extra tail portion is provided with the temporary tail member 7. The backfill injection material 16 is injected using the backfill injection mechanism 8 to ensure the stability of the natural ground 15.

(Wide widening method: second step)
Next, before switching to the construction of the enlarged mine 14c of the shield tunnel 14, the general mine 14a includes a blocking mechanism 12 that blocks the extra digging portion as shown in FIG. The standard cross-section segment 9b with the blocking mechanism and then the standard cross-section segment 9a are assembled while the shield excavator 1 is advanced.
Thereafter, injection of the backfilling injection material 16 into the overfilling portion by the backfilling injection mechanism 8 is stopped, and as shown in FIG. 3C, the overfilling portion is blocked before and after in the tunnel axis direction. Thus, the blocking mechanism 12 is arranged.

  In the present embodiment, a water stop plate made of a steel plate is used for the blocking mechanism 12. The water stop plate is formed in a cross-sectional shape similar to the widened cross-section 1b formed between the standard cross-section segment 9a and the ground pile 15 assembled in a ring shape, and the surface is directed in the axial direction of the tunnel. In this state, it is configured such that it can protrude and retract in the direction perpendicular to the tunnel axis from the standard cross-section segment 9b with a blocking mechanism. As shown in FIG. 7A, when the blocking mechanism 12 made of the water blocking plate protrudes into the extra-drilling portion, the protruding end surface comes into contact with the skin plate 2, Is completely blocked before and after the tunnel axis direction, and the region where the backfilling injection material 16 is injected is sealed and water is stopped.

  The blocking mechanism 12 is not necessarily limited to the above-described configuration. For example, a water stopping material discharging device may be applied to the blocking mechanism 12 and provided in the standard cross-sectional segment 9b with the blocking mechanism. As a result, the water stoppage improving material is discharged from the water stop improvement material discharge device to the position where it is desired to stop the water before and after the tunnel axis, thereby providing water stoppage to the backfilling injection material in the discharge range. The Rukoto.

(Widening method: third step)
Next, as shown in FIG. 4A, the temporary tail member 7 is removed from the skin plate 2, and a widening block 13 having a cross section similar to the widening cross section 1b as shown in FIG. It adheres to the outer peripheral surface of the standard cross-section segment 9a assembled in the second step.
Thereafter, as shown in FIGS. 4B and 4C, while the shield excavator 1 is advanced, the enlarged cross-section segment 9c is assembled to construct the enlarged pit 14c of the shield tunnel 14. Thereby, the shield tunnel 14 is widened from the general mine 14a to the enlarged mine 14c as shown in FIG.

  As described above, the shield excavator 1 extends the pressing jacks 11 arranged on the inner wall of the skin plate 2 with a predetermined spacing in the circumferential direction in the excavation direction, and behind the skin plate 2. The segment 9 or the thrust receiving piece 10 to be assembled is dug while being pressed. Accordingly, the widening block 13 is fixed to the standard cross-sectional segment 9a and the enlarged cross-sectional segment 9c is assembled to the standard cross-sectional segment 9a so that the pressing force of the pressing jack 11 can be sufficiently resisted. Thereby, since the pressing force does not act on the blocking mechanism 12, the widening operation of the shield tunnel 14 can be performed while ensuring the safety of the portion where the general mine 14a is switched to the enlarged mine 14c.

  Next, a method for reducing the width of the tunnel will be described in detail with reference to FIGS. 5 and 6 show horizontal cross sections of the shield excavator 1 and the shield tunnel 14 as in FIGS. 3 and 4.

(Width reduction method: first step)
As shown in FIG. 5 (a), the skin in which the temporary tail member 7 has been removed while excavating the natural ground 15 with an enlarged cross section 1c that combines the standard cross section 1a and the widened cross section 1b using the shield excavator 1 An enlarged cross section segment 9c is assembled in the plate 2 to construct an enlarged pit 14c of the shield tunnel 14 having an enlarged cross section.

(Width reduction method: second step)
Next, at the switching position of the shield tunnel 14 to the construction of the general mine 14a, as shown in FIG. 5 (b), with the widening block in which the widening block 13 having the same cross section as the widening cross section 1b is fixed to the outer peripheral surface. Assemble standard cross-section segment 9d.
Thereafter, the shield excavator 1 is advanced, and the temporary tail member 7 is attached to the skin plate 2 as shown in FIG. 5 (c), and the inside of the skin plate 2 as shown in FIG. 6 (a). A standard cross-section segment 9b with a blocking mechanism that embeds a blocking mechanism 12 that blocks the region having the widened cross section 1b before and after the tunnel axis is assembled.

  Note that the widening block 13, the blocking mechanism 12, and the standard cross-sectional segment 9 b with the blocking mechanism that encloses the blocking mechanism 12 use the same members as those used in the method for widening the shield tunnel 14 described above. Further, if the widening block 13 has an end face on the surface in the tunnel axis direction, the blocking mechanism 12 is not necessarily used.

(Narrowing method: third step)
Next, the shield excavator 1 is excavated while assembling the standard cross-section segment 9a, and as shown in FIG. 6 (b), the blocking is performed so as to block the region having the widened section 1b before and after the tunnel axis direction. The mechanism 12 is arranged.
Thereafter, the standard cross-section segment is assembled while the shield excavator 1 is advanced, and the general mine 14a of the shield tunnel 14 is constructed in the region having the standard cross-section 1a. Thereby, the width of the shield tunnel 14 is reduced from the enlarged mine 14c to the general mine 14a.

At this time, since the region having the widened cross section formed between the standard cross section segment 9a and the natural ground 15 becomes an extra excavation portion, the rear portion provided in the temporary tail member 7 at the extra excavation portion. The backfilling injection material 16 is injected using the filling injection mechanism 8 to ensure the stability of the natural ground 15.
Incidentally, in the region having the wider section 1b, a region serving as the expansion becomes wider pit 14b provided in the pit 14c region and Yohori Ri part, because they are blocked by stopping water by the blocking mechanism 12, These backfilling injection materials 16 do not leak into the enlarged pit 14c.

  According to the above-described configuration, the shield excavator 1 removes the temporary tail member 7 that is detachably installed behind the skin plate 2 to remove the enlarged cross-sectional segment 9c, and attaches it to the standard cross-sectional segment 9a. Since both of them can be assembled, it is not necessary to build an enlarged pit 14c having an enlarged cross section over the entire length of the shield tunnel, and it is economical, and its construction is simple and workability is good, which greatly reduces the construction cost and the construction period. It is possible to contribute.

  Furthermore, since the temporary tail member 7 can be used repeatedly, there is no need to newly prepare a plurality of temporary tail members 7 even when the shield tunnel 14 repeats expansion and contraction over its entire length, so that the widening pit 14b can be economically produced. It becomes possible to construct a shield tunnel comprising

  Further, since the backfill injection mechanism 8 and the chamber 4 are communicated with each other and excavated sediment can be supplied from the chamber 4 to the backfill injection mechanism 8, cement water and an admixture are mixed into the excavated sediment during supply. Since excavated soil can be processed and reused as backfilling injection material 16, it can be injected into the surplus area, greatly reducing the construction costs such as disposal and transport costs related to residual soil disposal, and The amount generated can be suppressed, and it is possible to greatly contribute to environmental considerations.

According to the tunnel widening method, the standard cross-section segment 9b with a blocking mechanism is assembled before the shield tunnel 14 is switched from the general mine 14a to the enlarged mine 14c. After assembling the standard section segment 9d with the widening block to which the widening block is fixed at the switching position to the general mine 14a, the widening cross-sectional area is blocked before and after the tunnel axis direction at a predetermined position by using the blocking mechanism 12. The widened cross-sectional area that is located adjacent to the general pit 14a and that corresponds to the surplus portion can be blocked. As a result, even when switching the tunnel from the general mine 14a to the expansion mine 14c or from the expansion mine 14c to the general mine 14a, the surplus portion adjacent to the general mine 14a can be easily stopped, so the workability is good and the construction cost is high. It is possible to greatly contribute to the reduction and shortening of the construction period.

  In addition, since the excavation cross section by the shield excavator 1 corresponds to an expanded width section that combines the standard section and the expanded section over the entire length, even if the shield tunnel 14 repeats expansion and contraction in the middle, the ground is not affected. It becomes possible to construct without considering the structures built on the ground.

  Furthermore, since the shield tunnel 14 can be mechanically constructed in a uniform procedure even when the shield tunnel 14 is constructed for the ground whose ground conditions change as the digging progresses, Compared to this, it is possible to construct a shield tunnel with better workability and safe and high quality.

It is a figure which shows the outline of the shield excavator used in the widening method and the narrowing method of the tunnel based on this invention. It is a figure which shows the cross section of the shield excavator. It is a figure which shows the widening method (the 1) of the tunnel which concerns on this invention. It is a figure which shows the widening method (the 2) of the tunnel which concerns on this invention. It is a figure which shows the width reduction method (the 1) of the tunnel which concerns on this invention. It is a figure which shows the width reduction method (the 2) of the tunnel which concerns on this invention. It is a figure which shows the cross section of the shield tunnel constructed | assembled by the widening method and narrowing method of the tunnel which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shield excavator 2 Skin plate 3 Cutter 4 Chamber 5 Earth removal apparatus 6 Tail packing 7 Temporary tail member 8 Backfill injection mechanism 9 Segment 9a Standard section segment 9b Standard section segment 9c with a shut-off mechanism Expanded section segment 9d Standard section with a widening block Segment 10 Thrust receiving piece 11 Press jack 12 Blocking mechanism 13 Widening block 14 Shield tunnel 14a General mine 14b Widening pit 14c Widening pit 15 Natural ground 16 Backfilling injection material

Claims (2)

A tunnel widening method using a shield excavator that builds both a general mine having a standard cross section and an expanded pit composed of an expanded cross section including a wide pit having a widened cross section in the general mine ,
The shield excavator includes a skin plate having a cross section similar to the enlarged cross section, a cutter located in front of the skin plate and excavating a general mine and a widening pit, behind the skin plate, and an inner periphery thereof. A temporary tail member that is detachably disposed between the surface and the outer peripheral surface of the standard cross-section segment assembled in a ring shape and has a cross-sectional shape similar to the widened cross-section,
While digging with an enlarged cross section that combines the standard cross section and the wide cross section using the shield excavator , the standard cross section segment is assembled within the skin plate with the temporary tail member attached, and a general pit is formed in the standard cross section area after excavation. A first step to build,
A standard cross-sectional segment containing a blocking mechanism for blocking an extra portion of the widened cross-sectional area before and after in the tunnel axis direction in the general mine, and then excavating while assembling the standard cross-sectional segment, and then using the blocking mechanism to A second step of blocking the digging portion before and after the tunnel axis direction;
The temporary tail member is removed from the skin plate, and a widening block having a cross section similar to the widening cross section is fixed to the outer peripheral surface of the standard cross section segment assembled in the second step, and then the shield excavator is used for excavation. A method for widening a tunnel, comprising a third step of assembling an enlarged cross-section segment and constructing an enlarged pit in an enlarged cross-sectional area after excavation. A method of reducing the width of a tunnel using a shield excavator that builds both a general mine having a standard cross section and an enlarged pit composed of an expanded cross section including a wide pit having a wide cross section in the general mine ,
The shield excavator includes a skin plate having a cross section similar to the enlarged cross section, a cutter located in front of the skin plate and excavating a general mine and a widening pit, behind the skin plate, and an inner periphery thereof. A temporary tail member that is detachably disposed between the surface and the outer peripheral surface of the standard cross-section segment assembled in a ring shape and has a cross-sectional shape similar to the widened cross-section,
Using the shield excavator, while digging with an enlarged cross section that combines the standard cross section and the wide cross section, the enlarged cross section segment is assembled within the skin plate from which the temporary tail member has been removed, and an enlarged pit is formed in the enlarged cross section area after excavation. A first step to build,
After assembling a standard cross-section segment in which a wide block having a cross section similar to the wide cross-section is fixed to the outer peripheral surface, the standard cross-section segment is assembled and a temporary tail member is attached to the skin plate. Process,
A method for reducing the width of a tunnel, comprising a third step of assembling a standard section segment while excavating the shield excavator and constructing a general pit in the standard section area after excavation.

Images